One-piece fastening or clamping devices are well known and are used for a variety of purposes. In one application, band clamps are used to secure electric shielding or insulation about electric wire. In another application, band clamps are used to secure pipe or other couplings to hose connections. Generally, however, fastening and clamping devices, such as band clamps, are used to reduce the size of any gap between the object constrained and the band adjacent thereto. Consequently, it can be appreciated that a one-piece band clamp is useful in any number of situations since it is not necessary to carry separate band sections and buckles and a tool to assemble them.
One type of commercially available one-piece planar cable-tie, made by the assignee of the present invention, includes a buckle section having a width greater than the remaining band body which is insertable therein. The cable-tie is produced by a method, such as stamping or die cutting, that cannot fully utilize the band material. Specifically, due to the extra width of the buckle section as compared to the band body, material between adjacent cable-ties is necessarily wasted during the manufacturing process.
A clamping device that is useful for numerous clamping jobs is disclosed in U.S. Pat. No. 4,896,402 to Jansen et al., issued Jan. 30, 1990 and entitled "Cable Tie." The device is a one-piece cable tie that utilizes a multi-planar buckle section through which the free end of the band is inserted. Jansen et al. also discloses that the cable tie is preferably made by a machine process in which the clamps are alternately formed on opposing sides of a sheet of metal material. The machine process must utilize this procedure because the buckle section is significantly wider than the overall band. Consequently, this fabricating process wastes material and adds a step to the manufacturing process which reduces efficiency. Moreover, the resulting clamp, when properly secured, results in a relatively high-profile clamp buckle and band interface.
Another one-piece clamping device is disclosed in U.S. Pat. No. 4,896,402 to Young, issued Jun. 21, 1988 and entitled "Band Clamp with Formable Buckle." The device comprises a multi-planar buckle section and a planar band body section. The device is fabricated by stamping a buckle section with "wings" perpendicular to the band's body section. The wings are then folded toward each other in abutting relation to form an opening. Finally, the wings are welded or braised together at the abutting ends to form the continuous loop of the buckle. This process not only produces a high-profile clamp buckle and band interface, but the initial stamping process wastes material and the bending and welding processes are both expensive and time consuming.
In U.S. Pat. No. 4,646,393, also to Young, issued Mar. 3, 1987 and entitled "Clamping Band for Electromagnetic Shielding Band Cable Connector," a one-piece clamping device for use in constraining electromagnetic shielding is disclosed. This device also comprises a multi-planar buckle section and a planar band section. The buckle includes a pair of abutting wings that are welded together after being folded to create a single, longitudinally extending opening.
Another commercially available one-piece cable tie, that has been made by the assignee of the present invention, includes a buckle having a raised section with slots formed on opposing sides of the raised section. The raised section, forming a high- profile buckle, is formed by punching the buckle in two opposing directions. However, the buckle side edges are flat and not raised.
A further integral band clamp is disclosed in U.S. Pat. No. 4,541,146 to Giannone, issued Sep. 17, 1985 and entitled "Clinching Clamp Device and Method of Attachment." The band comprises a multi-planar buckle which utilizes an "anchor" section to securely fasten the band to the encircled objects. The buckle and anchor are formed by taking an elongated strip of readily bendable metal and making a series of at least two convolutions of the band which have been bent at right angles to the device. The convolutions are wound in such a manner as to define a through-going passageway. This process of manufacture is inefficient because the step of twisting the band to produce a through-going passageway is expensive and time-consuming.
Other one-piece clamps are illustrated in U.S. Pat. No. 356,083 to Schrader, et al., issued Jan. 11, 1887 and entitled "Clamp for Hose Couplings" and U.S. Pat. No. 157,032 to Smith, issued Nov. 17, 1874 and entitled "Bail-Ties." Schrader, et al. describes a hose clamp having a number of projections that can be folded to provide a buckle. In the Smith patent, wings integrally formed with the band are bent over to engage portions of the band. The manufacture of both these devices necessarily requires the utilization of either wasteful metal stamping or expensive bending and welding techniques.
A one-piece cable tie is also described in U.S. Pat. No. 3,660,869 to Caveney, et al., issued May 9, 1972 and entitled "One-Piece Cable Tie." This tie is characterized by the use of a row of teeth disposed on one longitudinal surface of the strap. The patent also describes a plastic molding process for making the cable ties. Similar devices are disclosed in U.S. Pat. No. 4,272,870 to McCormick, issued Jun. 16, 1981 and entitled "Synthetic Plastics Tie Member" and U.S. Pat. No. 4,507,828 to Furutsu, issued Apr. 2, 1985 and entitled "Bundling Belt Device." The cable ties of McCormick and Furutsu are also manufactured using plastic molding techniques.
Although one-piece clamps or cable ties and the process of their manufacture are relatively well known, there is a need for a method for manufacturing a one-piece clamping device having a low profile buckle, that can be produced quickly, inexpensively and without waste of material.